We are currently studying how parts of the visual system deal with different types of stimulus movement. Neurons in the inferior pulvinar and alpha division of the lateral pulvinar respond to stimuli moving while animals hold their eyes stationary. Many of these cells respond over a wide range of velocities from a few degrees per second to several hundred degrees per second. Many cells in both of these areas do not respond to comparable motion of the same stimulus when it is generated by an eye movement. This ability to distinguish between real and self-induced stimulus motion persists when tested in a darkened environment. These observations suggest that the lack of response with an eye movement is not due to visual factors and may be generated by a corollary discharge. Cells with these properties are also found in the superior colliculus but not visual cortex, both of which project to the pulvinar. Hence, the collicular pathway may mediate this process. These studies suggest that one function of this part of the visual system is in dealing with non-visual influences on the processing of visual image motion.